But here indicates a contrast. In 2 Cor. 8 and 2 Cor. 9 the apostle spoke pleasantly to the dear saints in Corinth, encouraging them to have fellowship in the ministry to the needy saints in Judea. Immediately after that, he desired to make himself more clear to them by vindicating, with a severe and unpleasant word, his apostleship, even his apostolic authority. This was needed because of the vague and clouded situation caused by the false, Judaistic apostles (2 Cor. 11:11-15), whose teaching and assertion of what they were had distracted the Corinthian believers from the fundamental teachings of the authentic apostles, and especially from the proper realization of Paul's standing as an apostle.